The present invention relates generally to the feeding of lids of containers, and more particularly, is directed to a lid infeed system using a vacuum.
Conventionally, in order to transport container lids, a plurality of lids in stacked relation to each other, ride on two spinning rods which are adjacent and parallel or closely parallel to each other. As the rods spin, the lids are caused to move forwardly thereon.
A feed plate assembly is provided adjacent and above the spinning rods and has an opening at an inlet end with a width slightly greater than the width of a lid so that one lid can fit therein. In order to separate the lids from each other and push the forwardmost lid into the feed plate assembly, a spring is provided immediately adjacent the opening of the feed plate assembly and a timed eccentric cam arrangement pushes the spring down into engagement with the top of the forwardmost lid, serving to bias the forwardmost lid into good friction engagement with the spinning rods. As a result, the forwardmost lid is moved into the opening of the feed plate assembly by the friction engagement with one of the spinning rods.
The lids travel through the feed plate assembly and exit an outlet opening thereof, where they are adhered to a vacuum wheel having openings through which a vacuum is applied.
In many cases, the lids have lips which nest within each other in the stack. As a result of this nesting arrangement, it is sometimes difficult to disengage the forwardmost lid from the remainder of the stack, which may result in the machine being shut down.
Still further, due to the purely mechanical arrangement of the spring and spinning rods, it is possible that the spring may not engage the forwardmost lid with the correct force, so that there may be too much force, causing problems with bending or transporting of the lid, or too little force, which may result in too little friction with the spinning rods.
An arrangement is also known using similar apparatus, but with a rotatable finger that serves to push the forwardmost lid into the inlet opening of the feed plate assembly. Such apparatus is sold by F & L Machinery Design, Inc. of Edison, N.J. However, there is still a problem of disengaging the forwardmost lid from the remainder of the stack due to the lips of the lids and the nesting arrangement thereof, which may result in the machine being shut down.